The present invention relates to redundant power supply systems, and more particularly to providing a monitoring circuit to detect failure of isolation devices in redundant power supply systems.
While the size and speed of electronic components have received much focus and attention in the advancement of digital technology, ensuring proper power delivery to the components has remained a concern. The various branches within a system that rely on a power supply tend to be numerous and require differing levels of power. As the number of components within a system increases, the chance for failures and damage of the power supply of a system also increases.
Typically, a plurality of redundant power supplies is utilized to ensure proper power delivery and integrity within electronic systems. The parallel arrangement of power supplies within a redundant power supply system often employs an isolation device. The isolation device, usually referred to as a switching OR-ing MOSFET, within each power supply acts as a mechanism to protect the power system bus from shorting in the situation that one of the power supply nodes shorts to ground. While the OR-ing MOSFET does provide rudimentary isolation capabilities, if the OR-ing MOSFET itself shorts, the system is unable to detect that condition. Unfortunately, when shorted itself, the ability to provide isolation is lost, and any other failure that causes the associated power supply node to short to ground will cause the entire power system to crash. Accordingly, a need exists for a technique to detect and indicate the presence of a failure of an isolation device in a redundant power supply system. The present invention addresses such a need.
The present invention provides aspects for failure detection of an isolation device in a power supply of a redundant power supply system. The aspects include an isolation device coupled to a voltage input line of a power supply. A comparator coupled to the isolation device provides a predictive failure analysis (PFA) signal when the isolation device fails.
Through the present invention, a straightforward and effective approach to detecting and signaling presence of a failure condition for an isolation device in a power supply of a redundant power supply system is achieved. These and other advantages of the present invention will be more fully understood in conjunction with the following detailed description and accompanying drawings.